Baseboard thermostat



Patented Sept. 8, 1936 MSW PATEN Lawrence M. Persons,

a corporation of liowa lites Moines, Iowa, assignor to Penn Electric Switch Ca, Des Moines; liowa,

Application January 24, 1934, Serial No WWW? 17 Claims. (fill. 2@l3;8)

An object of my invention is to provide a thermostat adaptable for use along a baseboard or the like or for use in any other position, the thermostat being of simple, durable and comparatively 5 inexpensive construction.

More particularly it is my object to provide a thermostat in which a switch mechanism is encased with the exception of at least one side thereof, a bimetal or other temperature responlO sive element being formed to act as such side to enclose the switch mechanism in conjunction with the rest of the casing, yet the bimetal element is thus in a position to be well aerated, which is essential to the proper operation of the switch structure if it is desired to have it accurately respond to the temperature of the surrounding atmosphere.

A further object is to provide a switch structure in which switch mechanism is entirely en- 20 closed but the temperature responsive element for actuating it is exterior of the enclosure for the switch mechanism, thus being in a position for most complete and eifective aeration.

A further object of the invention is to provide 25 a switch mechanism enclosed against the en-- trance of dust, yet having a bimetal element which is well aerated and which may form a part of the enclosure for the switch mechanism.

With these and other objects in view my in- 30 vention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accom- 35 panying drawing, in which:

Figure 1 is a perspective view of a switch structure embodying my invention.

Figure 2 is a front elevation of the same with the cover removed. 40 Figure 3 is a longitudinal sectional view on the line 3-3 of Figure 2.

Figure 4 is a transverse sectional view on the line 44 of Figure 3; and

Figure 5 is a front elevation with parts broken 45 away showing a modified form of the invention. On the accompanying drawing I have used the reference numeral l to'indicate a back wall of a casing. The casing II) has end walls l2 and I4 and side walls l6 and I8. The walls l4 and I6 50 may be omitted, as shown in Figure 5, if desired. A front wall is provided which may be snapped into position on the walls l0, l2, l4, l6 and I8 by means of spring clips 22 entering depressions 24 in the walls l6 and I8. 55 Within the switch casing switch mechanismis provided consisting in general, of a switch arm 26,

a magnet 28, an armature 3 and switch contacts 32 and 35. The switch arm 26 is pivoted by means of a leaf spring 36 on a bracket 38. The magnet 28 is carried by an upstanding flange lil of a bracket 52. The brackets and 32 are secured. to the base or back wall iii by means of rivets l or the like.

The contact 32 is carried by the switch arm 36 while the contact 3 5 is carried by a leaf spring 436. 1 The leaf spring 66 is secured as by rivets it-3 to the flange ill of the bracket 12. A channel shaped bar 50 is secured to the leaf spring 36 by means of a rivet or the like 52. Means is provided for adjusting the channel shaped bar 5D and the leaf spring 46 and thereby the contact 3 3 relative to the contact 32. This means consists of a threaded set screw 54 having a serrated head held in any adjusted position by a leaf spring 56. The leaf spring 56 extends from a plate 58 having ears 60 located in openings 62 formed in the flange 40 of the bracket 42. A single screw 64 is used to hold the plate 58 in position.

I provide a bimetal or other type of temperature responsive element 66. It is L shaped to either follow the walls I 4 and E6 or, as in Figure 5, act as a substitute for these walls. Adjacent the angle of the L the bimetal element engages a pair of projections 68 on the wall l4 and the outer end of one leg of the bimetal element as indicated at 10 engages the wall l4. The projections 68 have shouldered ends .69 extending through apertures in the bimetal element 66.

The outer end of the other leg of the bimetal element 66 as indicated at 12 is adapted to engage the wall l6 which acts as a stop for the bimetal element when its long leg, shown horizontally in Figure 2, warps toward the switch mechanism.

The bimetal element 66 is operatlvely connected by means of a thrust bar 14 to the switch arm 26. The switch arm has a finger 16 for this purpose entering a slot 18 in the thrust bar 74. The thrust bar 14 extends loosely through an opening 80 of the wall l6. Where the wall I6 is omitted, as in Figure 5, no opening of this character is needed. The connection between the bimetal element and the thrust bar consists of a reduced portion 82 of thethrust bar extending through a slot in the bimetal element.

For adjusting the range of operation of the switch structure, Iprovide an adjusting screw 84 threaded into the wall l4 andhaving an adjusting knob 86. A set screwailis adapted to pre vent rotation of the knob 86 relative to the adjusting screw 84.

The set screw 88 can be loosened at the factory whereupon the adjusting screw 84 can be set for the normal range of operation of the switch and the knob 86 can then be set at the central position of Figure 1 and the set screw 88 tightened to retain this setting. Then when a higher or lower temperature than normal is desired, the knob 86 can be swung to the right or left from its position at right angles to the walls In and 20. The knob 86 and the bimetal element 66, it will be noted enter quite nicely into the design of the casing.

In Figure 5 the walls [4 and I6 are omitted; portions [4a,l4b, l6a and l6b only being left for supportingpurposes. In both types of switches, the bimetal element is exposed to the atmosphere and thus well aerated which is a requisite for accurate operation of the thermostat. Such a construction' also eliminates providing a casing for the switch mechanism together with the bimetal element which casing has to be well perforated for aeration and thus readily permits the entrance of dust to accumulate on the switch mechanism.

In my construction, however, the dust is excluded either by the six walled casing or by the four walls, shown in Figure 5 and the bimetal element itself acting as the other two walls. The walls l0 and 20, it will be noted in Figure 3 have overhanging portions "la and 20a between which the bimetal element 66 is mounted and which are slightly spaced from the edges of the bimetal element to thus allow its free movement but reduce the space for entrance of dust to a minimum.

The bimetal element 66 may be made to warp toward the switch casing upon either a rise or a drop in temperature, depending on whether a heating means or a cooling means or humidifier is to be controlled by the switch.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the'real spirit and purpose of my invention and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

1. In a thermostat construction, switch mechanism, a casing for enclosing said switch mechanism with the exception of at least one side of said casing being open, a plate-like temperature responsive element covering said open side of said casing with the exception of slight spaces between the edges of said temperature responsive element and said casing, said temperature responsive element being operatively connected with said switch mechanism.

2. In a thermostat construction, switch mechanism, a casing for enclosing said switch mechanism with the exception of at least one side of said casing being open, a temperature responsive element covering said open side of said casing with the exception of slight spaces between the edges of said temperature responsive element and said casing, said temperature responsive element being operatively connected with said switch mechanism, and an adjustable knob on said temperature responsive element for changing the range thereof. I

3. In a thermostat construction, switch mechanism, va partial casing therefor, a relatively flat, wall-like bimetal element formed to complete said casing and operatively connected with said switch mechanism and an adjustable knob on said temperature responsive element for changing the range thereof.

4. In a thermostat construction, switch mechanism, a. rectangular casing therefor comprising a front, a back and two walls anda relatively fiat, wall-like bimetal element forming the other two walls thereof, having its edge slightly spaced from said front and back and operatively connected with said switch mechanism.

5. In a thermostat construction, switch mechanism, a rectangular casing therefor comprising a front, a back and two walls and a bimetal element forming the other two walls thereof, said bimetal element being L shaped, and operatively connected with said switch mechanism.

6. In a thermostat construction, switch mechanism, a rectangular casing therefor comprising a front, a back and two walls and a bimetal element forming the other two walls thereof, said bimetal element being L shaped and anchored adjacent the angle of the L, one leg of said bimetal element being anchored and the outer end of the other leg being operatively connected with said switch mechanism.

'7. In a thermostat construction, switch mechanism, a rectangular casing therefor comprising a front, a back and two walls and a bimetal element forming the other two walls thereof, said bimetal element being L shaped and pivoted adjacent the angle of the L, the outer end of one leg of said bimetal element being engaged with one end of said two walls, adjusting means engaging the intermediate portion of said leg between the pivoted angle thereof and said end and the outer end of the other leg being operatively connected with said switch mechanism.

8. In a thermostat construction, switch mechanism, a rectangular casing therefor comprising a front, a back and two walls and a bimetal element forming the other two walls thereof, said bimetal element being L shaped and pivoted adjacent the angle of the L, the outer end of one leg of said bimetal element being engaged with one end of said two walls, adjusting means engaging the intermediate portion of said leg between the pivoted angle thereof and said end and the other end of the other leg being operatively connected with said switch mechanism and being engageable with the other end of said two walls which acts as a stop in one direction therefor.

9. In a thermostat construction, switch mechanism including an armature and a magnet, a 1

rectangular casing for said switch meclfiagiism comprising a front, a back and two walls, bimetal element forming the other two walls of said casing, said bimetal element being L shaped and pivoted adjacent the angle of the L, the outer end of one leg of the L being engaged with one end of said two walls, adjusting means engaging the intermediate portion of said leg between the pivoted angle and said end thereof, the outer end of the other leg being operatively connected with said armature to move it toward and away from said magnet, the other end of said two walls being engageable with said endof said other leg to actas a stop therefor in one of its positions.

10. In a thermostat construction, switch mechanism including an armature and a magnet, a rectangular casing for said switch mechanism comprising a front, a back and two walls, a bimetal element forming the other two walls of said casing, said bimetalelement being L shaped and pivoted adjacent the angle of the L, the

outer end of one leg of the L being engaged with one end of said two walls, adjusting means engaging the intermediate portion of said leg between the pivoted angle and said end thereof, the outer end of the other leg being operatively connected with said armature to move it toward and away from said magnet.

11. In a thermostat construction, switch mechanism, including an armature and a magnet, a rectangular casing for said switch mechanism comprising a front, a back and two walls, a bimetal element forming the other two walls of said casing, said bimetal element being L shaped and anchored adjacent the angle of said L, one leg of said bimetal element being anchored and the outer end of the other leg being operatively connected with said armature to move it toward and away from said magnet.

12. In a thermostat construction, switch mechanism including an armature and a magnet, a rectangular casing for said switch mechanism comprising a front, a back and two walls, a bimetal element forming the other two walls of said casing, said bimetal element being L shaped and operatively connected with said armature to move it toward and away from said magnet.

13. In a thermostat construction, switch mechanism including an armature and a magnet, a

partial casing therefor and a bimetal element formed to complete said casing and operatively connected with said armature to move it toward and away from said magnet.

14. In a thermostat construction, switch mechanism, including an armature and a magnet, a casing for enclosing said switch mechanism with the exception of at least one side of the casing being open and a temperature responsive element covering the open side of said casing and operatively connected with said armature to move it toward and away from said magnet.

15. In a thermostat construction, a switch mechanism, a switch casing therefor at least partially enclosing said switch mechanism, two walls of said casing being in overhanging relation to the body of the casing and a bimetal element operatively connected with said switch mechanism and having its edges located between said overhanging portions and said edges being slightly spaced therefrom.

16. In a thermostat construction, switch mechanism, a casing therefor and a bimetal element for said switch element, said bimetal element being L-shaped and pivoted adjacent the angle of the L, the outer end of one leg of said himetal element being engaged by said casing, ad justing means engaging the intermediate portion of said leg between the pivot angle thereof and said end, and the outer end of the other leg being operatively connected with said switch mechanism.

17. In a thermostat construction, switch mechanism including an armature and a magnet, a casing for said switch mechanism, a bimetal element for said switch mechanism, said bimetal element being L-shaped and pivoted adjacent the angle of the L, the outer end of one leg of the L being engaged with said casing, adjusting means engaging the intermediate portion of said leg between the pivot angle and said end thereof, the outer end of the other leg being operatively connected with said armature to move it toward and away from said magnet.

LAWRENCE M. PERSONS. 

